contace lenses color

I recently bought some blue contact lenses but because my eyes are so dark, you wouldn't be able to see them. I already own some all white contact lenses (that are basically white on both sides) and thought that if I attached the blue ones onto the white ones and placed the contacts on my eye (from the white side) you would be able to see them. This was in fact the case after I tried them on. Is this in any way unsafe?